Sequential responding in accordance with temporal
relational cues: a comparison of before and after.

Abstract:

The current study investigated the relative effects of Before and
After relational cues on temporal order judgments. In Experiment 1,
participants (N = 20) were exposed to a 5-phase temporal relational
responding task. Participants observed a sequence of 2 familiar shapes
and then completed either a Before or an After statement to describe the
sequence. Response speeds were significantly faster for Before
statements than for After statements. Experiment 2 (N = 24) extended
Experiment 1, using abstract rather than familiar stimuli, and
replicated the findings. The current data extend previous research,
which employed temporal relational responding tasks as a measure of
cognitive abilities such as intelligence, by focusing on differences in
speed between responding in the presence of relational cues used in such
tasks. The differences in response speeds observed between Before and
After cues suggest that more work is needed to understand the specific
processes that underpin such responding.

The ability to understand and sequence events may be attributed in
part to the relations we derive between events and objects. These
relations range from simple physical discriminations, such as size
(e.g., A is larger than B, B is smaller than A), to more complex ones,
such as analogy (e.g., A1B1 is to C1D1 as A2B2 is to C2D2). Early work
on transposition posited the idea that people often respond to stimuli
based on the stimuli's relative properties (e.g., choosing the
brighter of two stimuli) as opposed to their absolute properties (e.g.,
responding to stimuli of a certain brightness; e.g., Herbert &
Krantz, 1965; Reese, 1968). More recently, researchers (e.g., Sidman,
1994) have argued that equivalence relations may provide a behavioral
account of development of language and similar cognitive processes.
Relational frame theory (RFT) in turn extended equivalence research,
positing that language-able humans can learn to respond in accordance
with derived relations other than Same and Different (Hayes,
Barnes-Holmes, & Roche, 2001).

Most experimental analyses of relational responding employ response
accuracy or acquisition as dependent variables. Recently, however, a
number of studies have used response time measures to explore
differences in responding in accordance with derived relations (Bush,
Sidman, & de Rose, 1989; Fields, Adams, Verhave, & Newman, 1990;
Fields & Verhave, 1987; O'Hora, Roche, Barnes-Holmes, &
Smeets, 2002; Spencer & Chase, 1996; Steele & Hayes, 1991).
Steele and Hayes (1991) investigated three types of relational
responding: Same, Different, and Opposite. Response latencies were
calculated to measure differences in responding to the combinatorially
entailed Same relations that were the result of combining either Same
(e.g., If A is the same as B and B is the same as C, then A is the same
as C) or Opposite relations (e.g., If A is the opposite of B and B is
the opposite of C, then A is the same as C). Participants responded more
quickly in accordance with combinatorially entailed relations based on
trained Same relations (i.e., shorter response latencies) than with
those based on Opposite relations. The authors suggested that the longer
reaction times for Opposite-based relational responding were due to
deriving a different relation from that trained. A similar study by
O'Hora et al. (2002) compared latencies of mutually entailed
relational responses (e.g., if A is the same as B, then it can be
derived that B is the same as A). The research focused on the relations
More Than, Less Than, Same, and Opposite. In More Than and Less Than
relations, the mutually entailed relation is different than that trained
(e.g., If A is more than B, then B is less than A, whereas if A is the
same as B, then B is the same as A).

The Before/After relation allows humans to verbally sequence
behaviors in a particular order. Many daily routines, such as getting
dressed and making breakfast, require us to arrange subroutines in
particular sequences (e.g., boiling a kettle requires filling the kettle
with water before heating it). One key difference between Before and
After statements relates to the coordination of the verbal descriptions
with the event (see Clark, 1971). In this line of research, the idea of
coordination referred to descriptions of events with Before cues and how
these descriptions coordinate with the temporal order in which the
events occur (e.g., "Fill the kettle before you heat it"). In
contrast, although descriptions that employ After relational cues denote
the same actions, they describe the event in a reverse order (e.g.,
"Heat the kettle after you have filled it"). An alternative
interpretation of children's responding in the presence of Before
and After cues was put forward by Amidon and Carey (1972). They asserted
that the difficulty arises from the presence of a subordinate clause.
The study consisted of children responding to instructions containing
both Before and After cues with subordinate clauses (e.g., "Move
the red plane after you move the blue plane") and instructions with
no such clauses (e.g., "Move the red plane first; move the blue
plane last"). The latter instruction still maintains the temporal
order of the events but does not contain a subordinate clause. Amidon
and Carey's views contrasted with Clark's semantic
hierarchical account, as the relations First/Last should still exhibit
the same features of time, simultaneity, and prior that Before/After
exhibit. It could therefore be suggested that children understand
temporal order quite well, just not when Before and After occasion
subordinate clauses.

There have been few studies of temporal relational responding
within the relational responding paradigm. O'Hora, Pelaez, and
Barnes-Holmes (2005) investigated the correlations between Before/After
relational responding and performance on verbal subtests of the Wechsler
Adult Intelligence Scale-Third Edition (WAIS-III; Wechsler, 1997).
Participants were tested on a behavioral model of instructional control
for Before and After relational responding and were subsequently
required to complete several subtests of the WAIS-III. It was found that
successful completion of the complex relational task was correlated with
higher scoring on the Vocabulary subtest of the Verbal Comprehension
index of the WAIS-III. More specifically, moderately strong correlations
were observed between temporal relational task scores and correct
responses on the Vocabulary subtest. O'Hora et al. (2008) further
investigated the relationship between temporal relational responding and
intelligence. Specifically, the study examined whether performance on
relational responding tasks would predict performance on the four
indices of the WAIS-III. Based on RFT predictions, it was expected that
high performance on relational responding tasks would predict similar
performance on the Verbal Comprehension and Perceptual Organization
indices. These expectations were developed on the premise that
relational ability underpins many verbally based cognitive abilities. It
was also expected that responding scores would not predict scores on the
other two indices, Working Memory and Processing Speed, because the
procedure did not require more than minimal input from memory. The
predictions were supported through subsequent analysis, with
participants who successfully completed the temporal relational task
scoring high on the Verbal Comprehension and Perceptual Organization
indices but not on the Working Memory or Processing Speed indices. These
findings support RFT claims that such relational ability underlies a
number of cognitive abilities.

A recent study by O'Toole and Barnes-Holmes (2009) extended
O'Hora et al.'s (2005) findings on relational responding and
intelligence scores by using response time as an indicator of fluency in
relational responding tasks. The relational responding task used by
O'Toole and Barnes-Holmes was the Implicit Relational Assessment
Procedure (IRAP; see Barnes-Holmes et al., 2006), during which
participants were required to respond to or agree with statements that
were either consistent (e.g., spring before summer) or inconsistent
(e.g., spring after summer). The IRAP works on the premise that
responding to consistent trials will be faster than responding to
inconsistent trials. The difference in response latency was found to
correlate negatively with measures of intelligence. Specifically, they
found that the smaller the differential between consistent and
inconsistent trials, the higher the score on the measure of intellectual
flexibility. This led the authors to suggest that their procedure may
provide a measure of intellectual flexibility. Though interesting,
O'Toole and Barnes-Holmes's procedure differed substantially
from that of O'Hora et al. O'Hora et al. compared responding
to Before and After relations, while O'Toole and Barnes-Holmes
examined the difference between responding to consistent (or
well-established) relations and inconsistent relations, regardless of
whether the relations were Before or After. They found that those who
scored higher on the intelligence test exhibited greater relational
flexibility, the ability to respond in conflict with globally
well-established verbal relations.

The findings of Steele and Hayes (1991) and O'Hora et al.
(2002) have important implications, as they suggested that responding to
such relations (i.e., Before/After instructions) takes more time. Both
O'Hora et al. and Steele and Hayes used response latency
measurements--the latter explored response differences between mutually
entailed relations containing Same and Opposite relational cues, and the
former extended this by also looking at More Than and Less Than. These
studies demonstrated the importance of measuring response latencies for
such responding, as differences in the relative time taken for
responding to these relations were found. In line with the Clark (1971)
notion of Before/After coordination, if a participant is presented with
an A ... B sequence, a corresponding Before description would coordinate
with it (e.g., if A.,.B, then A before B), but if the corresponding
description consisted of an After cue, a relation must be derived in
order for the participant to choose the stimuli in the correct sequence
(e.g., if A ... B, then B after A). Responding to After cues may take
more time to construct, so it is expected that the response speed for
After instructions would be slower than for Before instructions.

The current study attempted to extend understanding of Before/After
relational responding by employing both accuracy and response time
measures to investigate differences between the specific Before and
After relational cues. Verbally describing sequences of events involves
using the relational cues of either Before or After (e.g., Al before Bl,
B1 after Al). Describing sequences using Before requires a repetition of
the observed sequence, but describing sequences using After requires a
reversal of the observed sequence. Based on the findings of Clark (1971)
and the research on coordination and combinatorially and mutually
entailed relations by Steele and Hayes (1991) and O'Hora et al.
(2002), this reversal is likely to require more time to provide the
description. Experiment 1 measured the speed of order judgments that
included either Before or After relational cues. It was expected that
the response speed of After judgments would be slower than that of
Before judgments.

Experiment 1

Method

Participants. Twenty undergraduate and postgraduate students (5
male and 15 female) at the University of Ulster participated in this
study. Written informed consent was obtained from all participants. All
participants were experimentally naive. No financial reward or research
credit was offered in exchange for taking part. All participants were
over 18 years of age, spoke English as their first language, and did not
have a language disorder. Participants were randomly assigned to one of
the two groups, Before-After (BA) or After-Before (AB), before the
experiment began.

Materials and apparatus. Participants were seated in 2 m x 2 m
experimental cubicles in the psychology laboratory. There were two types
of stimuli used in the current study (see Figure 1): those used in
observed sequences and those used in the response array. The stimuli
used in the observed sequences consisted of four familiar shapes
(circle, square, triangle, and cross) and were 4 [cm.sup.2] in area. The
stimuli presented in arrays after the observed sequence cleared from the
screen were the same four geometric shapes but with an area of 1.5
[cm.sup.2]. Size was set using the IrfanView program (Skiljan, 2007).
The English words before and after were used as relational cues in the
subsequent response statements. These were black, capitalized, and set
in bold, 24-point Times New Roman font. The present study was programmed
by the first and second authors in Visual Basic 6.0. A Fujitsu Siemens
Scenic 300 personal computer and accompanying 15-inch CRT monitor were
used for stimulus presentation. Responses were made in each trial by
clicking with a standard computer mouse.

[FIGURE 1 OMITTED]

Procedure. Participants were exposed to a five-phase sequential
responding procedure (see Figure 2). The five phases are referred to as
Before Training, Before Probes, After Training, After Probes, and Mixed
Probes. There were 12 trial types in the Before Training phase. Each
trial type comprised two geometric shapes in a particular sequential
order (e.g., circle ... square; cross ... triangle). All four geometric
shapes were randomly assigned to a particular position in the sequence,
with all permutations of shape and order presented once in a quasirandom
order (see Figure 3). Thus, participants were exposed to each of the 12
trial types once in a quasirandom order.

Instructions for the Before Training phase were presented as
follows:

In a typical Before Training phase trial, participants observed a
sequence of two shapes, randomly chosen from the pool of four. The first
shape appeared in the center of a white screen for 1,000 ms. The screen
cleared for a 1,000-ms interstimulus interval (ISI), which consisted of
a blank white screen. The ISI appeared at several points between
stimulus--stimulus and stimulus--response presentations. The second
shape appeared after the ISI for 1,000 ms and was replaced by another
1,000-ms ISI. After the second ISI, a grey message box containing the
words "Click Here" appeared in the center of the screen (see
Figure 3). After the participant clicked the message box, the screen
cleared and a black line appeared, marking out the bottom quarter of the
screen. Beneath the black line, two arrays of four shapes were
positioned at the bottom of the screen, one on the left hand side and
one on the right. The position of the message box also controlled for
mouse cursor position, with the mouse icon equidistant from each shape
in the array, positioned at the center of the word BEFORE (see Figure
3). The word BEFORE was positioned at the bottom center of the screen,
separating the arrays. Participants were required to click on one of the
four shapes in the bottom left of the screen and then on one of the four
shapes in the bottom right (see Figure 3). Correct responding on trials
reflected the order in which the shapes in the sequence had just
appeared. In a typical example, the sequence of circle followed by
square was presented. In the presence of the Before relational cue,
choosing the circle in the left array followed by the square in the
right array was correct, as the observed sequence was circle before
square.

Feedback was provided in the form of the messages
"Correct" in green writing, to reinforce correct responses,
and "Wrong" in red writing after incorrect responses.
Participants were required to choose a shape from the left array
followed by a shape from the right array, so responding from right to
left resulted in negative corrective feedback, Once feedback had been
given, an intertrial interval (ITI) consisting of a blank white screen
appeared for 1,000 ms before the next trial was presented in exactly the
same manner. This continued until all 12 trials had been presented in a
quasirandom order. Participants were required to demonstrate responding
at a criterion level of 11 out of 12 trials in order to move on to the
Before Probes phase. Failure to reach criterion resulted in retraining
on the Before Training phase. A maximum of 10 exposures to the Before
Probes phase was provided. Failure to demonstrate responding at mastery
level within this number of exposures resulted in the termination of the
study. See Figure 2 for an illustration of experimental progression.

The following instructions were presented to participants at the
beginning of the Before Probes phase:

The Before Probes phase was identical to the Before Training phase,
except that no feedback was presented for responses. Participants
demonstrating mastery criterion on Before Probes progressed to the After
Training phase, and those who failed Before Probes were exposed to
retraining on the Before Training phase. Upon completion of the Before
Probes phase, the following After Training phase instructions appeared:

The After Training phase was identical to the Before Trainig phase
except that the relational cue After, instead of Before, was presented
between the arrays. All trial typesn outlined in the Before Training
phase were the same as for the After Training phase. In the example
outlined above, in the presence of the After cue, choosing the square
followed by the circle would be correct, as the statement would
correctly describe the observed sequence Square after Circle. The
mastery criterion was identical to the previous two phases, and those
who were successful progressed to the After Probes phase. Failure to
respond at mastery level resulted in retraining on the After Training
phase.

After Probes instructions were presented to participants as
follows:

The After Probes phase was identical to the After Training phase
apart from the absence of feedback. Those who achieved mastery criterion
proceeded to the Mixed Probes phase. Failure resulted in retraining on
the After Training phase.

Mixed Probes instructions were presented as follows:

The Mixed Probes phase was a 24-trial phase, in which all trial
types were presented twice, once in the presence of the Before
relational cue and once in the presence of the After cue. Feedback was
not given in this phase, and mastery criterion was set as 21 correct
responses out of 24 possible trials. Successful completion of the Mixed
Probes phase resulted in the conclusion of the experiment. Failure to
demonstrate mastery criterion level resulted in further exposure to the
Mixed Probes phase.

In the BA group, participants were exposed to the phases in the
following order: Before Training, Before Probes, After Training, After
Probes, and Mixed Probes. In the AB group, the order of phases was as
follows: After Training, After Probes, Before Training, Before Probes,
and Mixed Probes. This controlled for any learned order and facilitation
effects of the relational cue.

Results and Discussion

The raw data consisted of accuracy and reaction time scores for
each participant for each of the five experimental phases. All 20
participants completed the experiment within nine blocks. There were 10
participants in the BA group and 10 participants in the AB group.

Accuracy data. Accuracy data are presented in Tables 1 and 2. Eight
of the 20 participants reached mastery criterion on all five phases at
the first attempt (four in the BA group and four in the AB group). An
additional eight participants completed the Before Training phase on the
first attempt (four in the BA group and four in the AB group), with
three of the remaining four requiring one additional exposure (one in
the BA group and two in the AB group) and one participant (in the BA
group) requiring three additional training blocks before reaching
criterion.

All participants, including those who required additional exposure
to the Before Training phase, passed the Before Probes on the first
attempt. Apart from the eight participants who passed all phases on the
first attempt, one additional participant (from the BA group) passed
After Training on the first attempt, and an additional nine participants
reached criterion on the second exposure (three in the BA group and six
in the AB group). Two more participants (from the BA group) required
three exposures before reaching criterion. All participants passed the
After Probes phase on the first attempt. Eighteen participants completed
the Mixed Probes phase on the first exposure (eight in the BA group and
10 in the AB group), with one participant (from the BA group) requiring
one additional exposure and the remaining participant (from the BA
group) requiring two exposures to reach criterion. See Tables 1 and 2
for participant progression in both control groups.

Response speed data. There are two measures of speed calculated.
First, reaction time data were analyzed in terms of response speed,
which was taken as the reciprocal of the response latency in seconds (1
divided by the latency in seconds; see Hall, Sekuler, & Cushman,
1969, for an overview on calculating response speed). The Mixed Probes
phase response speeds were used in the analysis between groups (see
Figure 4 for an illustration of the findings). In the Mixed Probes
phase, the mean response speed in the BA condition was faster for Before
probes (A4 = 0.67, SD = 0.13) than for After probes (M = 0.56, SD =
0.15). The AB group also yielded similar differences between means of
Before (M = 0.63, SD = 0.09) and After (M = 0.54, SD = 0.09) probes. The
mean response speed also exhibited faster average responding rates for
Before probes (M = 0.65, SD = 0.11) than for After probes (M = 0.55, SD
= 0.12) in both groups. There were no notable differences between Before
probes in the BA group (M = 0.67) and Before probes in the AB group (M =
0.63). Similarly, no notable differences were found between mean
response speeds on After responding in the BA group (M = 0.56) and
responding in the AS group (M = 0.54). Average response speeds across
both BA and AB for Before probes (M = 0.65) and After probes (M = 0.55)
corresponded to reaction times of 1.54 s and 1.82 s, respectively.

The second reaction time measure analyzed was interresponse times
(IRTs), which corresponded to the latency between choosing the first and
second stimulus from the response array. When choosing the first and
second stimulus from each of the comparison arrays, it is possible IRTs
would be significantly faster in Before responding than in After because
of associative conditioning. In other words, the second response made in
the sequence may be primed by its association with the first comparison
response. Response speeds were calculated using the procedure outlined
previously. Mean IRT speeds for Before (M = 1.04) and After responding
(M = 1.02) were calculated across both groups. A second two-way 2
(response type: Before/After) x 2 (response order: BA/AB) mixed ANOVA
was conducted to investigate whether there were differences in IRTs when
participants described sequences using either Before or After cues. No
differences were found in the IRTs for both response types, F(1, 16) =
0.38, p = 0.546. There were also no differences in responding across
control groups, F(1, 16) = 0.013, p = 0.91, and no significant
interaction, F(1, 16) = 0.03, p = 0.862.

Experiment 1 investigated how humans verbally respond to stimulus
sequences and how employing particular temporal cues (e.g., Before or
After) can affect time taken to describe such sequences. Participants
responded significantly faster when asked to describe sequences with
Before cues than with After cues, irrespective of the order in which
responding to these cues was trained.

One issue with Experiment 1 concerned the use of Visual Basic
(Microsoft, 1998) to measure response speeds. Previous research (Andre,
Ghio, Cave, & Teston, 2003; Asaad & Eskandar, 2008) identified
potential technical problems with some types of stimulus presentation
programs that may lead to the inaccurate measuring of response speeds.
One feature they identified as affecting precise measurement was the
unplanned delays caused by parallel background processes and
applications. The program used in the current study was developed in
Microsoft Visual Basic Version 6.0, which is a high-level language that
operates on a non--real time operating system, Microsoft Windows.
Consequently, we were unable to control for background processes that
compete for computational power with stimulus presentation programs and
may have induced delays in the response measures. One way to control for
this potential problem is by programming stimulus presentations in
low-level languages (e.g., C++) that allow the user to control and
inhibit background processes. Alternatively, software packages such as
Presentation or E-Prime provide easy-to-use development environments
that set controls on background processes and stimulus presentation
hardware in order to maximize temporal resolution. It may be argued that
the results obtained in Experiment 1 could have been subject to temporal
measurement problems as outlined above.

Experiment 2 sought to control for such problems. Nevertheless, in
the current experiment, Before and After trials were presented randomly
during the critical test sessions, so it is unlikely that there was a
directional bias caused by the lower temporal resolution. In fact, the
likely effect of lower temporal resolution would have been to increase
overall variability and make it less likely to obtain a significant
difference between conditions.

Employing familiar stimuli in Experiment 1 may have made it more
likely that participants would verbalize the relationship between the
sequence stimuli as they observed them. That is, as the participants
watched a circle appear followed by a square, they may have verbalized
the rule "circle before square." This is especially likely
because they were aware that they would be asked to judge the order of
these stimuli. It is therefore possible that the higher response speeds
were due to the correspondence between the required judgment and a rule
verbalized while watching the sequence. Hoith and Arntzen (1998)
reviewed numerous studies that investigated the effects of stimulus
familiarity on equivalence class formation and found that participants
found it easier to derive relations between familiar stimuli than
between unfamiliar stimuli. Similarly, Arntzen (2004) found that
equivalence class formation occurred more readily when participants were
exposed to familiar stimuli earlier in equivalence training. According
to Arntzen, this may be due to familiar nameable stimuli facilitating
partitioning of novel stimuli into equivalence classes, as such stimuli
are already grouped based on their verbal labels. Indeed, much research
has been conducted in the past 20 years identifying the effects of
exposure to arbitrary and nonarbitrary stimuli (e.g., O'Connor,
Rafferty, Barnes-Holmes, & Barnes-Holmes, 2009).

In addition, in the literature related to working memory (Baddeley
& Hitch, 1974), Hulme, Maughan, and Brown (1991) explored the
effects of long-term memory on short-term memory span, the largest
number of verbal stimuli that can be recalled in the learned serial
order. Hulme et al. compared words and nonwords to demonstrate long-term
effects on recall and found a significantly higher recall of words than
of nonwords. As the procedure in Experiment 1 used nonarbitrary stimuli,
it could be argued that respondents benefited from this when
establishing stimulus relations. It may be posited, based on the above
studies, that differences could be found between relations containing
arbitrary and nonarbitrary stimuli.

Based on these issues, novel, unfamiliar stimuli were employed for
Experiment 2. The experimental program used for Experiment 2 was written
in E-Prime Version 2.0, in order to enhance the temporal resolution of
the response measures. Furthermore, based on the assertions of Holth and
Arntzen (1998) and Arntzen (2004), novel arbitrary stimuli were used for
each experimental phase, so that responding on Phase 2 and subsequent
phases could not be attributed to a history of responding to the
experimental stimuli.

Experiment 2

Method

Participants. Twenty-four undergraduate and postgraduate students
(9 male and 15 female) from the University of Ulster participated in
this study. The same recruitment criteria outlined in Experiment 1 were
also used for Experiment 2. Participants were once again randomly
assigned to one of two groups, the BA group or the AB group. Written
informed consent was obtained from all participants.

Materials and apparatus. The setting and computer used were exactly
the same as for Experiment 1; however, the software program and stimuli
differed. The program was written by the first and second authors in the
E-Prime Version 2.0 software application suite. This experiment differed
from Experiment 1 in that arbitrary, rather than nameable, stimuli were
employed (see Figure 5). Furthermore, novel stimulus sets were employed
for each phase. As in Experiment 1, stimuli presented in observed
sequences were 4 [cm.sup.2] in area, and stimuli presented in the
descriptive arrays were 1.5 [cm.sup.2] in area. Stimulus sizes were
controlled for using Irfanview (Skiljan, 2007). The English words before
and after were used as relational cues in the present study. These cues
were capitalized and set in bold, black, 24-point Times New Roman font.
The fixation point was black in color and was positioned in the center
of the screen. During training, feedback in the form of the messages
"Correct" and "Wrong" were presented in green and
red, respectively, 24-point, bold Times New Roman font.

[FIGURE 5 OMITTED]

Procedure. Experiment 2 was procedurally similar to Experiment 1.
The following section only describes the methodological differences
between Experiments 1 and 2. In the current experiment, each phase had
an exclusive pool of four arbitrary shapes. As described in Experiment
1, participants in the BA group were exposed to the phase order Before
Training, Before Probes, After Training, After Probes, and Mixed Probes,
and participants in the AB group were given the phase order of After
Training, After Probes, Before Training, Before Probes, and Mixed
Probes.

An outline of a typical trial can be seen in Figure 6. As in
Experiment 1, there were 12 trial types in the first four phases. In the
sequences at the beginning of each trial, two shapes appeared in a
randomly assigned order. All permutations of two shape sequences were
presented once in a quasirandom order. Participants were required to
concentrate on the sequence of two shapes in the center of a screen. The
first stimulus appeared for 1,000 ms, and then the screen cleared for an
ISI of 1,000 ms. A second stimulus then appeared for the same duration,
and the screen subsequently cleared for an ISI. After the second 151, a
fixation point appeared in the same position as the shapes in the center
of the screen. The fixation point persisted for 1,000 ms.

The fixation point was replaced by an array of four shapes to the
left center of the screen and an array of four shapes to the right
center of the screen. The word BEFORE appeared in the center of both
arrays. Each of the four shapes appeared once in both arrays, and the
position of the shapes within the array remained the same for all 12
trials in the phase. The relational cue and the mouse icon appeared in
the same position that the fixation point had been in before it was
replaced. This controlled for the position of the mouse icon, which was
equidistant from the comparison arrays. Participants were required to
choose one shape from the left side and then a shape from the right. As
in Experiment 1, mastery criterion was set at 11 correct responses out
of 12 trials for the first four phases and 21 out of 24 trials for the
Mixed Probes phase. Participants had only one exposure to the Mixed
Probes phase and therefore had only one attempt to reach criterion level
before the study ended. This was another difference between Experiments
1 and 2; this change was made to ensure responding on the Mixed Probes
phase was not a result of learning from repeated exposure.

Results

As in Experiment 1, the raw data consisted of accuracy and reaction
time scores for each participant for each of the five experimental
phases. A1124 participants completed the experiment. Twelve participants
were assigned to the BA group and 12 participants to the AB group. As in
Experiment 1, analysis was performed on the accuracy data. Acquisition
and responding was very high across both groups, similar to results in
Experiment 1. Reaction time data were further analyzed in terms of
response speed, and analyses were performed to explore differences in
the relational cue and across both BA and AB groups.

Accuracy data. All 24 participants completed the experiment.
Participants in the BA group completed the experiment phases in the
order of Before Training, Before Probes, After Training, After Probes,
and Mixed Probes, with participants in the AB group completing the
phases in the order of After Training, After Probes, Before Training,
Before Probes, and Mixed Probes.

Data from one participant in the BA group was omitted because the
average response speed in the Mixed Probes phase fell outside 1.5
standard deviations from the mean. The low average speed was not simply
caused by individual trial outliers; consistently low speed responding
across all trials contributed to this average as well. This was observed
in prior training trials, and training did not seem to increase response
speed. Two participants reached mastery criterion on all five phases on
the first attempt (two in the BA group). These data are presented in
Table 3. An additional 13 participants completed the Before Training
phase on the first attempt (three in the BA group and 10 in the AB
group), with 13 additional participants requiring one additional
exposure to reach criterion level (four in the BA group and two in the
AB group). Three participants required two additional exposures to reach
criterion level on the Before Training phase (three in the BA group).
All 24 participants passed the Before Probes phase on the first attempt.

In addition to the two participants who passed all phases on the
first attempt, an additional nine participants passed the After Training
phase on the first exposure (three in the BA group). An additional 12
participants passed After Training with one additional training block
(three in the BA group and nine in the AB group), with three
participants (from the BA group) requiring two additional exposures. Two
participants required three additional exposures before reaching
criterion level on After Training (one in the BA group and one in the AB
group), and one participant (from the AB group) required four additional
exposures. All participants, except for two (from the AB group), passed
After Probes on the first exposure, and 22 of the remaining 24
participants reached mastery criterion on Mixed Probes in the first
attempt. Two participants (from the AB group) did not reach criterion on
Mixed Probes. The results of these participants were omitted from
reaction time analysis. See Tables 3 and 4 for participant progression.

Response speed data. The Mixed Probes phase response speeds were
used in the analysis between conditions (see Figure 7 for an
illustration of the findings). Speed was calculated as the inverse of
latency responses. The mean response speed in the BA group was notably
faster for Before probes (M = 0.54, SD = 0.1) than for After probes (M =
0.48, SD = 0.13). The AB condition yielded similar differences between
means of Before probes (M = 0.5, SD = 0.12) and After probes (M = 0.46,
SD = 0.16). The mean response speed for Before probes in both groups (M
= 0.52, SD = 0.13) also exhibited faster average responding rates than
for After probes (M = 0.47, SD = 0.14). There were also small
differences between Before probes in the BA group (M = 0.54) and Before
probes in the AB condition (M = 0.5). Similarly, a small difference was
observed between mean response speeds on After probes responding in the
BA group (M = 0.48) and responding in the AB condition (M = 0.46).
Overall response speeds for Before probes and After probes corresponded
to reaction times of 1.92 s and 2.12 s, respectively.

A second two-way 2 (response type: Before/After) x 2 (response
order: BA/AB) mixed ANOVA explored the differences between response type
and response order in terms of IRTs. No differences were found in the
IRTs for both response types, F(1, 20) < 1, p = 0.7. There were also
no differences in responding across control groups, F(1, 20) < 1, p =
0.469, and no significant interaction, F(1, 20) < 1, p = 0.92.

[FIGURE 7 OMITTED]

In Experiment 2, it was established that response speeds were
significantly faster in sequences containing Before relational cues.
This experiment replicated the findings in Experiment 1. It was found
that responding to sequences containing arbitrary stimuli was not
different than responding to sequences containing familiar geometric
stimuli. In Experiment 1, stimuli were not replaced throughout phases.
Experiment 2 controlled for familiarity of stimuli through replacement
of stimuli in each phase.

General Discussion

The aim of Experiments 1 and 2 was to analyze the role of the
temporal relational cues Before and After in describing observed
sequences of stimuli. In Experiment 1, the procedure required
participants to respond to observed sequences of geometric stimuli by
describing such sequences using a relational statement containing either
a Before or an After cue. Participants demonstrated faster responding
when the Before cue was presented, suggesting that temporal coordination
between the sequence order and the relational statement affected
response speed. No differences were observed between the IRTs for Before
and After statements (i.e., response speed between choosing the first
and second stimulus in the statement). Experiment 2 replicated these
findings while making some methodological refinements. Perhaps most
important, these refinements included the use of novel stimuli for
testing. This precaution helps support the external validity of the
findings by ensuring that generalized relational responding, as opposed
to trained responding based on the exact conditional discriminations,
was being measured (e.g., Arntzen, 2004; Hoith & Arntzen, 1998;
Sidman, 1994).

Some variability can be observed in terms of progression across
relational cues. In other words, some participants required additional
training to achieve mastery criterion from Phase 2 probes on the first
relational cue to Phase 3 training on the second. This was not
considered for analysis in these experiments. This was primarily due to
participants' requiring more trials to understand the change in
coordination of the statement. In earlier pilots of the procedure, it
was found that instructing participants to respond from left to right
was not enough, as there was still a tendency to respond from right to
left. In other words, participants may have assumed that the change in
response cue required constructing the statement in the opposite
direction, rather than responding consistently to earlier phases and
choosing comparison shapes so that the statement coordinated with the
new cue. Perhaps more important, counterbalancing controlled for
differences in responding in the presence of both cues during the Mixed
Probes phase. The Mixed Probes phase was randomized; thus, responding
was not affected by expectancy. There is scope for future research to
develop a methodology to effectively test progression across cues, as
this will further identify differences in such responding.

Some researchers (e.g., Andre et al., 2003) have expressed concern
about the use of Microsoft Visual Basic as programming software for
developing tightly controlled stimulus displays. Even though we used
Visual Basic in Experiment 1, in Experiment 2, we used E-Prime to
control for measurement precision, and with this experiment, we
replicated the major findings of Experiment 1. The current study
provides tentative evidence that, under certain circumstances, Visual
Basic programs provide sufficient temporal accuracy to distinguish
between responses of interest. The latency differences observed between
conditions in the current experiments were in the order of 0.28 s for
Experiment 1 and 0.2 s for Experiment 2. These were also reliable across
participants (In Experiment 1, 18 of 20 participants were faster on
Before Probes than on After Probes. In Experiment 2, 18 of 22
participants exhibited faster responding during Before Probes). In such
circumstances, it seems that Visual Basic is suitable.

Both Experiments 1 and 2 demonstrate that participants are
significantly faster at describing temporal sequences when using a
Before relational cue than when using an After relational cue. The
methodology used in the current study provides an experimental paradigm
with which to analyze such relational responding in adult participants.
This was one novel attempt at developing and testing an experimental
procedure to investigate the differences between Before and After
temporal relations in describing particular sequences. This lends
support to previous findings (e.g., O'Hora et al., 2002; Steele
& Hayes, 1991) that responding in accordance with derived
combinatorial and mutual entailed relations that are different than
those trained takes longer than responding in accordance with derived
relations that are the same as those trained.

The present findings replicate those of Clark (1971), based on
research on early language development, that Before statements are
easier to understand than After statements. Moreover, these data extend
Clark's research through the use of adult participants. Clark
suggested that Before statements are easier because they preserve the
order in which stimuli are observed. Additional research remains to be
conducted on temporal relational responding, however, as previous
research has found no differences between forward (Before) and reverse
(After) temporal statements when less ambiguous terminology, such as
first and last, is used (Amidon & Carey, 1972). In addition, it is
not clear whether such effects are limited to temporal statements. For
instance, further research may investigate whether such reversal effects
are observed for statements about relative size (e.g., A ... b ... A is
bigger than b or b is smaller than A).

The response speed differences found in the current study may
suggest that a response judgment is made between the presentation of the
second stimulus in the observed sequence and the choice of the first
stimulus comparison. Donders (1869) analyzed response speeds in relation
to additive factors. This was based on the premise that two processes,
such as structuring and recognizing a sequence, require more time than
the single process of just recognizing the sequence. Similarly,
Sternberg (1966) discovered that the magnitude of the comparison digit
set increased response time on a digit search task when participants
were required to complete a memory recall task. More recent cognitive
research (e.g., Kanabus, Szelag, Rojeck, & Poppel 2002) showed that
in order for two stimuli to be correctly ordered in a temporal sequence,
the ISI between them would need to be at least 20 to 40 ms (see also
Hirsh & Sherrick, 1961). Similar studies have confirmed this ISI
value, suggesting that there may be a process underlying temporal order
when responding to audio, visual, and tactile stimulus relations that
are independent of the presented stimuli (e.g., Poppel, 1997).

Previous research into relational responding (e.g., O'Hora et
al., 2002; Steele & Hayes, 1991) has suggested that differences in
response latencies may be due to the nature of the relations involved.
O'Toole and Barnes-Holmes (2009), however, looked at the difference
in responding to familiar stimuli consistently (e.g., spring before
summer) versus inconsistently (e.g., spring after summer). The current
data could be seen to provide support for both theses. However, it is
possible that people have a greater history of responding to Before
cues, given that, temporally, this is how stimuli are generally
presented in the real world. It is possible, therefore, that the After
trials in the current study acted in a manner similar to that of the
inconsistent trials employed by O'Toole and Barnes-Holmes. One way
to test this proposition would be to train responding to After cues and
test to see if the differential in response latency compared to Before
cues was subsequently reduced.

Grayson and Wasserman (1979) suggested that short-term memory for
sequences of responses may play a role in temporal responding. A
particular two-item response sequence, if acting as a functional
operant, may be retained in short-term memory until reinforcement or
response differentiation takes place (Weisman & Dodd, 1979).
Wasserman, Nelson, and Larew (1980) proposed that animals, such as
pigeons, should demonstrate that memory for two-item response
differentiation should be available upon time of reinforcement. Pigeons
were trained to peck left and right keys in particular sequences upon
illumination of the keys, and the intervals between illuminations varied
from 0.5 s to 2 and 4 s. Results indicated that pigeons retained
sequence information until reinforcement and that responding was highest
in positive trials (i.e., those trials that were positively reinforced).
The ITIs between stimuli in the sequence and second stimulus response
and subsequent reinforcement were varied and measured across trials.
This was to explore whether interitem delay (duration between Stimulus 1
and Stimulus 2) or retention delay (duration between Stimulus 2 and
Response 1) would have a greater effect on responding. It was found that
increasing the retention level had detrimental effects on responding in
positive trials, whereas relatively little effect was found when the
interitem duration was varied. Future research could explore the effects
of ITI variation on sequential responding and whether response speed and
accuracy would decrease as a function of increased ITI.

One methodological limitation of note relates to the instructions
used at the beginning of the After Training and Mixed Probes phases of
Experiments 1 and 2. Within these instructions, participants were asked
to take their time and understand the sequences. The instructions used
at the beginning of the Before Training and Before Probes phases did not
include such a statement. Considering response speeds were recorded and
compared between Before and After trials in the Mixed Probes phases,
instructing participants to take their time may have resulted in slower
response speeds for After trials. Notwithstanding this limitation, the
inclusion of this statement should not have affected the validity of the
results, considering that response speeds were recorded and compared in
the Mixed Probes phase only. In this way, instructions were consistent
for responding across both relational statements. It is, however,
important that future refinements to this procedure control for such
instructional issues. The current data demonstrate a clear differential
in responding to two common temporal cues, Before and After. One
question that arises from the current study regards the effects of
memory on stimulus recall. In contrast to the findings of Hulme et al.
(1991), the current Experiment 2 provides support for the notion that
the ability to verbally process stimuli has no effect on responding to
stimulus sequences. Future research may attempt to extend the-current
research and investigate the specific differences in terms of memory
recall between novel and nonarbitrary stimuli. Varying the ISI between
presentations of stimuli may extend our understanding of this control
process, particularly in relation to both forward and reverse relational
cues. Similarly, varying the duration between second stimulus
presentation and comparison stimuli may reveal much about the effects of
short-term memory on serial recall. These variations will not only
identify important features of order judgments but also explore
conflicts between verbal statements and stimulus order and whether this
affects one type of relational statement more than another.

Part of the current research was presented at the Annual Convention
of the Association for Behavior Analysis, Chicago, May 2008.

The current research formed part of John M. Hyland's doctoral
thesis, completed at the University of Ulster while he was funded by the
Vice

Chancellor's research scholarship from 2006.

Correspondence concerning this article should be addressed to John
M. Hyland, School of Psychology, Dublin Business School, 13-14 Aungier
St., Dublin 2, Ireland. E-mail: john.hyland@dbs.ie

This phase of the experiment requires you to concentrate on a sequence
of 2 shapes at the top of the screen. One shape will appear for a
brief moment and then disappear. Another shape will then appear in the
same position for an equal amount of time. A second after the second
shape disappears, a message box will appear underneath. You are
required to click on the message box, which will reveal several shapes
on both the bottom left and bottom right hand sides of the screen
beneath a black line. You are required to choose one shape from either
side. In between both sets of shapes there is a word. This word will
in some way relate both shapes you choose.
In the experiment, one of two words will appear in different trials.
You will try to learn how this word relates the shapes during each
training session. You must respond from left to right in each trial.
In this first stage, you will be provided with feedback. When you're
ready, click on the button below.

This phase of the experiment requires you to respond in the same way
for each trial as Phase 1. Remember to respond from left to right in
each trial. The only difference in this phase is that no feedback will
be presented after each trial.
Good luck! When you're ready, click on the button below.

This phase of the experiment requires you to respond in the same way
for each trial as Phase 1. Feedback will be presented after each trial
in this stage. Remember to take your time and understand the sequence
of shapes and how they are related, depending on the word in between.
Good luck! When you're ready, click on the button below.

This phase of the experiment requires you to respond to shapes in a
certain sequence as in the previous phase. No feedback will be
presented after each trial in this phase.
Good luck! When you're ready, dick on the button below.

This phase of the experiment requires you to respond to the sequence
of shapes as in previous stages. No feedback will be presented after
each trial. Remember to take your time and understand each trial, and
to respond from left to right in all trials.
Good luck! When you're ready, click on the button below.